Binaural beats were discovered in the 19th century by a physicist called Heinrich Dove. He noted that when signals of different frequencies were received audibly (one to each ear), the human brain detects a phase variation between the frequencies and attempts to balance the difference. This generates certain waves which effect the human brain in many ways. Individuals use Binaural beats to help assist with pain, to sleep, to meditate, to increase awareness and productivity and to even have out of body experiences.
For maximum effect one should listen to Binaural beats through a set of head phones drawing in one frequency from one ear and another frequency from the other.